The Gordon Research Conference on "Oxygen Radicals in Biology" is designated to provide chemists, biologists, biochemists, cell biologists, clinicians, and other biomedical scientists with state of the art knowledge on reactive oxygen species in chemical and biological systems. This research conference is held every two years; the next meeting will be held February 6-11, 2000, at the Doubletree Hotel, Ventura, California. Ten conferences have been held since 1981 and they have proven to be extremely productive based on the large number of applicants and the post-meeting evaluations. Funds are requested to partially support travel, subsistence and registration costs for speakers from the United States and abroad and productive graduate students/post-doctoral candidates. The speakers listed in this program were selected based on suggestions from the previous chairs, co-chairs and attendees at the past conference. Virtually all speakers have accepted the invitation to present their latest research on oxygen radicals in biology. Topics to be covered included: 1) Antioxidants-regulation and molecular mechanism; 2) Redox regulation of glutathione; 3) Oxidases and peroxidases; 4) Oxidant induced transcription factors in cell signaling; 5) Nitric oxide and peroxynitrite; 6) Cytoprotective and cytotoxic effects of nitric oxide synthase and 7) Molecular mechanisms of diseases. In addition, Professor Louis Ignarro, the recipient of the 1998 Nobel Prize in Medicine, will present a Plenary Lecture entitled "Nitric oxide and Cyclic GMP Signal Transduction Mechanisms." Two separate poster sessions of two days each are scheduled for an anticipated 50-70 posters. Total attendance is limited to 135 by Gordon Conference rules. The Gordon Research Conference provides an excellent and needed forum for the diversity of both participants and research areas. The main strength of this Gordon Research Conference is the opportunities offered for scientists in different disciplines to interact in an extended and uninterrupted fashion. This type of interaction generally results in new collaborative research initiatives. The Gordon Research Conference on Oxygen Radicals in Biology plays a crucial role in exploring frontier research in this important and clinically relevant field.